Scientists discover massive planet as light and fluffy as fairy floss

[gary]

Originally Posted by ABC/AP 15 May 2024

Astronomers have identified a new planet that's bigger than Jupiter — the largest in our solar system — yet they say it's as fluffy and light as fairy floss.

The exoplanet named WASP-193b has exceedingly low density for its size, the international team of researchers reported in the Nature Astronomy journal on Tuesday.

The gas giants in our solar system like Jupiter and Saturn are much denser in comparison.

The lead author of the published study, Khalid Barkaoui, said WASP-193b is the second-lightest planet among the more than 5,400 planets discovered to date.

"The planet is basically super fluffy," the post-doctoral researcher from the Massachusetts Institute of Technology (MIT) said.

Story here :-
https://www.abc.net.au/news/2024-05-...iter/103849148

[xelasnave]

I call for irresponsible journalism to be implemented and have it clearly stated that this planet is indeed made out of fairy floss.

Thanks Gary


alex

[glend (Glen)]

It could be marshmallow. Although absolute mass maybe higher, but until we get a return sample mission we can not know for sure.

[iborg (Philip)]

Hi All


I have copied the abstract from the nature astronomy article (I believe this is not a copyright issue). I added the bold.


FYI - water is 1g/mL, depending on temperature.



Abstract

Gas giants transiting bright nearby stars provide crucial insights into planetary system formation and evolution mechanisms. Most of these planets show certain average characteristics, serving as benchmarks for our understanding of planetary systems. However, outliers like the planet we present in this study, WASP-193 b, offer unique opportunities to explore unconventional formation and evolution processes. This planet completes an orbit around its V-band-magnitude 12.2 F9 main-sequence host star every 6.25 days. Our analyses found that WASP-193 b has a mass of 0.139 ± 0.029 MJ and a radius of 1.464 ± 0.058 RJ, translating into an extremely low density of 0.059 ± 0.014g cm−3, at least one order of magnitude less than standard gas giants like Jupiter. Typical gas giants such as Jupiter have densities that range between 0.2 g cm−3 and 2 g cm−3. The combination of its large transit depth (1.4%), extremely low density, high-equilibrium temperature (1,254 ± 31 K) and the infrared brightness of its host star (K-band magnitude 10.7) makes WASP-193 b an exquisite target for characterization by transmission spectroscopy (transmission spectroscopy metric ~600). One single JWST transit observation would yield detailed insights into its atmospheric properties and planetary mass, providing a unique window to explore the mechanisms behind its exceptionally low density and shed light on giant planets’ diverse nature.